Good activities for muscle and skeleton fitness are push-ups, chin-ups and sit-ups. A weight programme can also be very good at building muscles and bone strength, but it`s better for teenagers to use smaller weights with many repetitions rather than big or heavy weights.

Make sure to avoid jerky movements; always be smooth and steady to avoid injury when you are doing these kinds of exercises. If you have special health needs, make sure to consult a physician before you take part in any exercise programme.